Research Questions

Project 1: How does pesticide exposure affect child development and timing of puberty?Project 2: How can we measure children’s exposure to pesticides and other environmental toxins?Project 3: Does pesticide exposure to children cause epigenetic changes that result in abnormal pubertal development?

Overview

Children of farmworkers in California are exposed to a unique mix of chemicals that may affect brain and reproductive system development. Potential exposures include the pesticides DDT and manganese (Mn) and polybrominated diphenyl ether (PBDE) flame retardants, which are prevalent in California due to the state's strict flammability standards. DDT, Mn and PBDEs are endocrine disrupting chemicals, which disrupt the body’s natural hormones to cause negative health effects. The keystone of this center is the CHAMACOS (Center for the Health Assessment of Mothers and Children of Salinas) study, a longitudinal cohort of primarily low-income, Mexican immigrant farmworker women and their children living in the agricultural Salinas Valley, California. The Center is studying the effects of pesticides in boys approaching puberty.

Project 1: Effects of Pesticide Exposure on Neurobehavior and Puberty
In girls, age at onset of puberty has declined in recent decades, but almost no studies have examined pubertal onset in boys. Pesticides like DDT and Mn along with PBDE flame retardants may impact pubertal onset and also jeopardize children's cognitive development. There is particular concern with exposures during pregnancy and early childhood, when brain growth is at its peak. This project is examining whether exposure to pesticides can impact pubertal onset and brain development.

Project 2: Pesticide Exposure to Farmworker Children
This project is continuing research into new methods to measure children’s environmental exposure to pesticides and other endocrine disrupting chemicals. Methods developed under this proposal have the potential to revolutionize the ability to assess exposures in studies of environmental health.

Project 3: Epigenetic Effects of Pesticides on Puberty
Epigenetic markers are changes in gene expression without changes in the DNA sequence itself. Epigenetic markers may be a key mechanism by which environmental exposures affect children’s health. In this project, researchers are investigating whether exposures to endocrine disrupting chemicals are associated with specific epigenetic markers. Researchers will also determine whether these changes are related to the age at onset of puberty.